For support and questions about SparkChess or chess in general, please see the links on the right and the Q&A section below.
That is a Promotion; a pawn will be promoted to queen (or other piece) if it reaches the last rank. Please consult the official chess rules for details.
Most likely you were the victim of an en-passant take. Don’t feel too bad, many casual players are not familiar with it. Please consult the official chess rules for details.
To castle, you move the king to the desired position – if castling is available, the rook will be moved automatically. Castling is not possible if the king or the rook has moved; or if the king is in check; or if one of the squares the king must travel is controlled by an enemy piece. According to the official FIDE rules, you can castle if the king was in check previously.
Try playing on Beginner (Cody). If you download the Full Version, you have access to some help tools that will help you make better moves.
Congratulations! You must be an advanced player; most likely you’ve played in tournaments. Our Chess AI was created to be fun and quick, not brutally strong. If you are an advanced player, you can still enjoy SparkChess’ multiplayer or by using its Board Editor and the PGN/Replay features.
Stalemate occurs when the player who must move is not in check but has no legal moves. This situation happens most frequently when the player has just the King left on the board and any move would place them in check.
A stalemate causes the game to end as a Draw, therefore the player who has the advantage should try to avoid it and checkmate instead, while the disadvantaged player may try to force a stalemate to avoid losing.
Playing chess online
They are the same product. When we created the first game engine in 2002, we called it flashCHESS. Later, in 2008 the third generation of the engine, rewritten from scratch, took the web by storm and we wanted to keep the name due to its heritage, naming it flashCHESS III. Later, to prevent any trademark complaints from Adobe regarding the use of “Flash”, we decided to rename the game as SparkChess.
SparkChess 7 is our newest release.
SparkChess® is registered trademark.
Yes. Online play is free, although we display unobtrusive ads from Google. If you prefer not seeing the ads, you can download the standalone version of the game.
The tools used to build the game are rather expensive. On top of that, there is the hosting, bandwidth, SSL certificates, code signing certificates, that must be considered. At the time of writing, we have over two million monthly page views, consuming a total of 500 GB of bandwidth. We are using a CDN and a performance monitoring service to maintain the quality of service.
Downloading and installing the Full Version
Yes. SparkChess is available as a standalone application on many platforms.
Linux support has proved problematic given the myriad of distros and configurations. Please contact us. You should also be able to run the Windows build with WINE.
Most likely the email sent to you was flagged as spam by your mail server or email application. Please check your Spam/Junk folder. If you can’t find it, please contact us. We’ll do our best to reply to you within two business days and will send you the game.
No. Start by either
- looking at your Downloads History (press CTRL+J / CMD+J in your browser to see the list) or
- looking into your Downloads folder or
- searching your computer files for “sparkchess”.
If you can’t find it or in the event you lost all the information on your computer, please contact us. At a minimum we’ll need the email address you used when purchasing but providing more details (payment method, transaction ID, receipt) will help speed up the process.
If you own an older version, you can upgrade using this upgrade form.
The preferred installation method is through Google Play.
We used to offer the game directly through our site so the following applies only for those who bought SparkChess directly from us: To install SparkChess on Android you must set your tablet/phone to accept installations from outside Google Play. Go to Settings → Applications and check the Unknown Sources option if it’s not already selected. Then you may download the SparkChess APK file either on a computer or directly on the Android device and tap on it to install.
You’re probably launching the free version by mistake. Don’t worry, it happens.
Let’s review the possibilities:
- if you purchased SparkChess for PC or Mac, you no longer need to play the game in your browser. You must locate the downloaded game and install it on your computer. Use CTRL/CMD+J from your browser to see the Download History and look for a file containing the word “sparkchess”, e.g. sparkchess7-setup.exe on PC or sparkchess7.pkg on Mac.
- On Android, pay attention to the game icons. The free version has the word “LITE” on the bottom right of the icon; the full version does not. Launch the Full Version (you can safely delete the free version to save up space).
Given the number of operating systems and devices SparkChess is available on, we’re trying to find the best match for you automatically. If you are on PC or Mac, you’ll be directed to buy the native app for your platform rather than the Chrome version. We think it would be a better choice for you. If you are sure you want SparkChess for Chrome, go to the Platform Selection page and choose the Chrome version from there.
If you have already purchased SparkChess for Windows or Mac and want it exchanged with the Chrome version, please contact us.
Google is changing the way Chrome Apps work. A combination of Chrome bugs and application format changes left us unable to update SparkChess Full Version. The existing version will misbehave in future versions of Chrome.
Still, we want you to keep enjoying SparkChess. You can either migrate to the desktop version of SparkChess for either Windows or Mac OS X, or you can play SparkChess in any browser, just not as a Chrome app. Please contact us, letting us know which solution you’d prefer.
We’re really sorry for the inconveniences but we’re doing everything in our power to support you.
SparkChess Lite for Chrome remains unaffected by the changes and we’ll keep supporting it.
Your payment represents a one-time license fee. Like most software, SparkChess is licensed, not sold. The license is perpetual (does not expire). Read the next question to see what’s included.
You get a license to use the game, access to the multiplayer service and free “point-releases”, i.e. if you buy version 7.0, you’ll get versions 7.1 through 7.9 for free, but not 8.0. Point-releases contain mostly bug fixes and improvements of existing functionality.
No. There are no monthly fees or subscriptions. Multiplayer access is free for the current version. If there’s a newer release than your version, multiplayer may or may not work, depending on the additional functionality we’ve added. We do our best to maintain backwards compatibility but we cannot guarantee it.
We certainly recommend you to upgrade, but the decision is up to you. Upgrading gives you access to new features and may correct any bugs we discovered. Also, as we improve and expand the multiplayer service, it may become incompatible with the older versions. The single-player experience never expires so you may continue to use the game for as long as you want.
The Desktop version of SparkChess (Windows, Mac and Chrome) is sold primarily through PayPal. We like PayPal because it benefits both ourselves as seller and you as buyer. Because Paypal’s fees are very small, we can keep prices low. You also get security (their security record is the best in industry and we don’t get to see your credit card details) and protection in case of disputes. You don’t even need to have a PayPal account.
Yes. There are no monthly fees, no subscriptions and no in-app payments.
Yes. Paying customers have priority access to the service and are also able to use the Chat feature. Free users can play only if the server capacity is below a certain threshold and have limitations on the number of games they can play daily. There are many other subtle differences, for example a free user account has a score cap of 10,000 points.
The principle is simple: Each player starts with 1000 points (2000 points for Premium users). When you defeat someone by checkmate, you win 10% of their score and they lose the same amount. This way, you will win more if you defeat a player with a high score, on the idea that you managed to win against a more powerful player. If the game ends in Draw or Stalemate, no points are given to either party. If a player resigns or disconnects, the formula is more complex, based on the number of moves in the game, if any player was in check at the time and which player had the overall advantage. This way we want to discourage cheating (disconnecting when at clear disadvantage). For a discussion about our score vs. Elo, see the next question.
Elo is the standard rating system for chess, recognized and understood by chess players worldwide. However Elo works best in controlled environments where cheating can be minimized. Online chess play is unsupervised. Players can cheat systematically, internet connections may drop and Elo would be meaningless because it takes into account just wins, losses and draws. Our system awards points even when the game terminates abruptly, user behavior and more. In the future we may combine Elo with our own scoring system.
We are parents ourselves and we’ve taken reasonable steps to make SparkChess Multiplayer a fun and safe environment for kids. Children under 13 do not provide any personable-identifiable information and may not use the Chat feature. We believe this is the safest way to ensure that they are not exposed to inappropriate language (filtering is done for English only). However, we cannot make any guarantees. We recommend parental involvement in any online multiplayer game. If you notice offensive words being used in usernames, we encourage you to submit them to our attention.
Filtering the players by subnet will only show players connected from the same network – usually the same physical location. Use this option to have your children see only opponents from the same household or nearby area.
We do not tolerate bullying, cheating or any other abusive behavior. If you have knowledge of such actions, please report the user’s nickname and their behavior.
Yes, if you can browse the web, you should be able to use the multiplayer service.
SparkChess Multiplayer was designed to connect through firewalls. Generally speaking, if you can browse the web, you should be able to use the service.
Check the Server Dashboard – if it reports that it’s up and there are people connected, the problem is local.
- If you have the free online version, the most likely cause is that you’ve exceeded the maximum number of daily matches or that there are too many players connected (users of SparkChess Premium have priority).
- if you have the Premium desktop version, some Antivirus programs include overzealous firewalls that may block SparkChess. You must grant access for SparkChess to access the Internet via port 80. If you’re unsure, temporarily disable any antivirus and firewall you may have installed and see if you can connect.
- if you have SparkChess for mobile devices, we noticed that DNS resolution seemed slower in some instances leading to timeouts in extremely rare cases.
Over 25,000 people use the SparkChess Multiplayer service every day.
SparkChess Multiplayer is built using Union Platform by User1 and hosted by leaders in cloud servers. We have load-balanced live servers located in New York City with automatic failover located in Seattle. We take daily offline backups. The quality of service is monitored 24/7 at 1 minute intervals.
In short, it doesn’t get any better than this in terms of speed and network reliability. While we do our best to keep the whole system running smoothly, it is a “best effort” service, provided with no guarantees. Why? Because it’s a free service. Rather than offering multiplayer for a select few at $5/month, we’re making it available for everyone.
Before anything else, try changing your password. If someone else connects with your username, you will get disconnected. It’s possible for someone to guess your password, so use a strong one.
Dropped calls happen even with paid services when dealing with multi-billion cell companies. SparkChess Multiplayer constantly monitors players’ internet connection. There’s a fine balance that we must keep between reliability and performance. If a connection is lost for over 2 minutes, the user is disconnected from the service.
Free accounts may be removed if unused for prolonged periods. From time to time we purge inactive accounts. The “grace period” is dynamic and calculated based on many factors. We do want to reward active users and we need to conserve resources (storage is not free and having a few Gb of unused accounts doesn’t help); we also need to backup the databases and maintain them, which requires more CPU power.
Premium users’ accounts are never removed.
Because the number of available players is changing constantly, Full Version owners may filter the Invitation list based on their preferences.
Currently the following filters are available:
- by score: with this filter enabled, only players within 10% of your score will be shown. So if you have 1000 points, you’ll see only players with at least 900 points and at most 1100 points.
- by subnet: The filtering is done by IP address. Only players with IP addresses from your “virtual neighborhood” are shown (technically speaking it’s a Class-C subnet). This usually means only players from the same building or block, although it depends on your Internet provider. This mode is perfect when you want to play with a coworker or at home with another person in the same house.
- by country: only players determined to be in the same country as you are shown. This method may not be always available. Players who’ve just created accounts may not have their country determined yet.
We should mention that your location (both the IP and the country) are safe. Another player cannot learn your location.
Login to the Multiplayer service, then from the main (invitation) window, go to My Account and click on the blue Facebook Logout button. That’s it. If you want to post the victories again, click on the same button again to login. You can deauthorize SparkChess completely from your Facebook App Center.
We’re listening to feedback from all players and add the features you want the most. Our goal is to make people think “Chess is Fun!”.
SparkChess uses a chess engine developed in-house with negamax, principal variation, iterative deepening, aspiration, quiescence, history heuristics and transposition tables. It has an opening database with about 7000 moves. The desktop version is multithreaded.
The original version took about three months, not including the time spent studying algorithms. The game is in active development in its sixth year. We make one major release each year and a few minor releases.
SparkChess uses iTunes to add, save and delete PGN files from your iOS device (iPhone or iPad).
On iOS, each app has its own separate Documents Folder. The files saved in those Documents Folders are accessible by iTunes. SparkChess can import and export PGN files to its own folder.
To add PGN files on your iOS device or to save a PGN file from the iOS device to your computer, open iTunes, click on the iPhone/iPad button at the top to connect to your device, then click on Apps. From the Apps tab, look at the File Sharing section. There are two panels there. Choose SparkChess from the left panel; on the right panel you’ll see SparkChess’ Documents (if any). To add a new PGN, click on “Add File…” button and select a PGN file from your computer. To save a file from the iOS device to your computer, select a PGN from the right panel a click on “Save to…” button. To delete a PGN file from your iPhone/iPad, right-click on the desired file from the right panel and choose Delete.
When you’re done, don’t forget to click on the Sync button at the bottom of the page!
In SparkChess, click on Replay and then on the Import or Export icons to load and save PGN files in the game’s Documents Folder.